Question

The function f(x) = 2.15(2x^2-4x-6) models the cost, in dollars, of a rug with width x feet. What is the cost of a rug that is 9 feet wide?

Answer 1

$258.

Explanation:

Plug in 9 for X.

Answer 2

$258

Explanation:

What we have is a function where we must plug an x value for the width of the rug, and we will get the cost.

What we need to do is substitute x = 9 in the equation:

`f(x) = 2.15(2x^2-4x-6)`

entering the value of x we get:

`f(9) = 2.15(2(9)^2-4(9)-6)`

solving the expression

`f(9) = 2.15(2(81)-36-6)\\f(9)=2.15(162-36-6)\\\\f(9)=2.15(120)\\f(9)=258`

the cost for a rug that is 9 feet wide is $258